Higher speed computers come with a cost—higher electrical consumption. For a small number of home PCs this extra power may be negligible when compared to the cost of running other electrical appliances in a household. However, in data center applications, where thousands or tens of thousands of microprocessors may be operated, electrical power consumption becomes important.
In addition, the power consumed by a microprocessor is transformed into heat. A pair of microprocessors mounted on a single motherboard can draw 200-400 watts or more of power. If that power draw is multiplied by several thousand (or tens of thousands) to account for the computers in a data center, the potential for heat generation can be appreciated. Thus, not only must a data center operator pay for electricity to operate the computers, it must also pay to cool the computers. The cost of removing heat may be a major cost of operating large data centers.
Large-scale Internet services require a computing infrastructure that can be described as a warehouse-sized computing system. The cost of building data center facilities having the capacity to deliver the power required by such a computing system can rival the recurring power consumption costs themselves.